Optimal On-Off Attitude Control for the Brazilian Multimission Platform Satellite

This work deals with the analysis and design of a reaction thruster attitude control for the Brazilian Multimission platform satellite. The three-axis attitude control systems are activated in pulse mode. Consequently, a modulation of the torque command is compelling in order to avoid high nonlinear control action. This work considers the Pulse-Width Pulse-Frequency (PWPF) modulator which is composed of a Schmidt trigger, a first-order filter, and a feedback loop. PWPF modulator holds several advantages over classical bang-bang controllers such as close to linear operation, high accuracy, and reduced propellant consumption. The Linear Gaussian Quadratic (LQG) technique is used to synthesize the control law during stabilization mode and the modulator is used to modulate the continuous control signal to discrete one. Numerical simulations are used to analyze the performance of the attitude control. The LQG/PWPF approach achieves good stabilization-mode requirements as disturbances rejection and regulation performance

Weak spatial-genetic structure in a native invasive, the southern pine beetle (Dendroctonus frontalis), across the eastern United States

The southern pine beetle, Dendroctonus frontalis, is a native pest of pine trees that has recently expanded its range into the northeastern United States. Understanding its colonization, dispersal, and connectivity will be critical for mitigating negative economic and ecological impacts in the newly invaded areas. Characterization of spatial-genetic structure can contribute to this; however, previous studies have reached different conclusions about regional population genetic structure, with one study reporting a weak east-west pattern, and the most recent reporting an absence of structure. Here we systematically assessed several explanations for the absence of spatial-genetic structure. To do this, we developed nine new microsatellite markers and combined them with an existing 24-locus data matrix for the same individuals. We then reanalyzed this full dataset alongside datasets in which certain loci were omitted with the goal of creating more favorable signal to noise ratios. We also partitioned the data based on the sex of D. frontalis individuals, and then employed a broad suite of genotypic clustering and isolation-by-distance (IBD) analyses. We found that neither inadequate information content in the molecular marker set, nor unfavorable signal-to-noise ratio, nor insensitivity of the analytical approaches could explain the absence of structure. Regardless of dataset composition, there was little evidence for clusters (i.e., distinct geo-genetic groups) or clines (i.e., gradients of increasing allele frequency differences over larger geographic distances), with one exception: significant IBD was repeatedly detected using an individual-based measure of relatedness whenever datasets included males (but not for female-only datasets). This is strongly indicative of broad-scale female-biased dispersal, which has not previously been reported for D. frontalis, in part owing to logistical limitations of direct approaches (e.g., capture-mark-recapture). Weak spatial-genetic structure suggests long-distance connectivity and that gene flow is high, but additional research is needed to understand range expansion and outbreak dynamics in this species using alternate approaches

Nesting in the lizard Phyllopezus pollicaris (Squamata: Phyllodactylidae) and a phylogenetic perspective on communal nesting in the family

Ninhadas comunais são encontradas em várias espécies de répteis. As hipóteses que explicam a evolução desse comportamento ainda são controversas, mas serão melhor compreendidas à medida que mais registros de ninhadas comunais forem descritos na literatura. Neste estudo, registramos duas ninhadas comunais de Phyllopezus pollicaris, incluindo a maior ninhada conhecida para a espécie. Este é o primeiro estudo a registrar ninhadas comunais para uma espécie de Squamata em uma região central do Cerrado. Além disso, também apresentamos fotografias das ninhadas, assim como medidas detalhadas e peso dos neonatos. As ninhadas foram encontradas durante a estação seca, em contraste com o padrão reprodutivo previamente descrito para a espécie na periferia do Cerrado. Nós também realizamos uma extensa revisão bibliográfica a respeito de ninhadas comunais na família Phyllodactylidae e apresentamos os resultados no contexto de uma árvore filogenética dos gêneros da família. Finalmente, sugerimos que estudar a correlação entre a evolução de ninhadas comunais e o investimento reprodutivo se tornará um campo de estudo fértil à medida que mais informações sobre ninhadas comunais estiverem disponíveis na literatura científica.Communal nesting occurs in many reptile species. The hypotheses that explain the evolution of such behaviours are still controversial, but will be better understood as more communal nesting records are described in the literature. We report the findings of two communal nests of Phyllopezus pollicaris, including the largest known nest for the species. Our study is the first to provide a communal nesting record for squamate species in a Cerrado core area. We provide nest photographs and detailed neonate measurements and weight. Nests were found during the dry season, in contrast with the reproduction pattern previously described for the species in the Cerrado periphery. We also conducted an extensive literature review seeking all available information on communal nesting information in Phyllodactylidae, and present this information in the context of a phylogenetic tree of phyllodactylid genera. We suggest that studying the correlation between communal nesting evolution and reproductive investment will become a fertile field as more information on lizard nesting becomes available in the literature

Prevalence of conventional cardiovascular risk factors in patients with acute coronary syndrome

Background: Primary prevention studies have shown that early detection and aggressive treatment of cardiovascular risk factors (CRF) prevent cardiovascular events. It is not well described the prevalence of CRF in patients, at the moment of admission due to acute coronary syndrome (ACS). Aim: To determine the prevalence of CRF among patients admitted with ACS. Methods: We analysed 4871 patients admitted consecutively in our coronary care unit with a diagnosis of ACS and included in a prospective registry, from January 2002 to October 2013. We studied the prevalence of conventional risk factors (diabetes, hypertension, smoking, dyslipidaemia) and compared findings according to gender and type of ACS: ACS with ST elevation (STEMI), ACS without ST elevation (NSTEMI). Results: Men represented 75% (n=3658) of the total population, were younger than women (61.6±12,9 vs 70.9 ±11.8 years; p<0.001) and had more frequently body mass index ≥ 25 kg/m2 (70.9% vs 62.3%; p<0.001). The most frequent CRF was hypertension (62.4%; n=3038), followed by dyslipidaemia (50.6%, n=2467), smoking (43.2%; n=2106) and diabetes (27.2%; n=1324). In women, the more common CRF were hypertension (75%) and dyslipidaemia (51.2%), whereas in men were smoking (54.4%) and dyslipidaemia (50.5%). We identify, at least, one CRF in 92,4% of all patients and two or three risk factors in 58.1%. Women had more frequently 2 CRF than men (40.1% vs 36.3%; p=0.011), although mean had, more often, 4 CRF (8.9% vs 4.1%; p<0.001). Previous history of cerebrovascular disease was more observed in women (8.6% vs 6.1%; p=0.002), but men had more often history of previous revascularization (9.8% vs 6.8%; p<0.001). On admission men presented more frequently STEMI (50.8% vs 43.5%; p<0,001) and less frequently renal dysfunction (17.2% vs 39.6%; p<0.001) and anaemia (18.8% vs 33.3%; p<0.001). Hypertension was the most prevalent CFR as in patients STEMI (56.6%) as in NSTEMI patients (67.9%), followed by smoking (47.5%) in STEMI patients and by dyslipidaemia (55.7%) in NSTEMI patients. Conclusion: We found at least one CRF in 92.8% of patients and two or three in more than half. Hypertension emerged as the major CRF in both forms of presentation of ACS

Conservação ambiental forte alcançada através de sistemas agroflorestais multiestratificados: 1 - agroflorestas e a restauração ecológica de florestas.

O objetivo deste trabalho foi verificar se um sistema agroflorestal multiestratificado (agrofloresta) agroecológico pode ser considerado como tendo uma sustentabilidade ambiental forte, com base em uma análise dos serviços ecossistêmicos de restauração florestal. Para tanto, foi utilizado resultados de pesquisas que compararam agroflorestas e regenerações naturais. Os resultados sugerem que as agroflorestas apresentam uma sustentabilidade ambiental forte e potencial de promover a restauração florestal, no entanto, é um sistema produtivo e não uma metodologia de restauração. Este fato, ao mesmo tempo em que impõe desafios legais e conceituais, aponta para uma alternativa de restauração para as florestas brasileiras.Edição do 1º Seminário de Agroecologia da América do Sul; 5º Seminário de Agroecologia de Mato Grosso do Sul; 4º Encontro de Produtores Agroecológicos de Mato Grosso do Sul; 1º Seminário de Sistemas Agroflorestais em Bases Agroecológicas de Mato Grosso do Sul, 2014, Dourados, MS - AGROECOL